The rise of an infamous group of workaholic hackers, collectively known as "Lazarus," who may be using secret lairs in northeast China and have created a virtual "malware factory" that could wreak a lot more havoc in the future.

Big caveat here: Lazarus doesn't reveal much about itself. What little is known about the group is speculative.

Nevertheless, extensive forensic research into its activities dating back almost a decade paints a fascinating, if chilling, picture of a hacker collective that is mercenary, tenacious and motivated by what appears to be a mixture of political and financial objectives.